1. Field of the Invention
The present invention relates to an image displaying apparatus in which electron-emitting devices are arranged in matrix, more particularly to a method and an apparatus for manufacturing an image displaying apparatus having a display panel on which a rear plate (RP) provided with electron-emitting devices arranged in matrix and a face plate (FP) provided with phosphors are arranged in opposing positions as a first image forming member and as a second image forming member, respectively.
2. Related Background Art
Conventionally, an electron-emitting device is roughly divided into two known types, i.e., a thermal electron-emitting device and a cold-cathode electron-emitting device. The cold-cathode electron-emitting device includes the field emission type (hereinafter referred to as the FE type), the metal/insulation layer/metal type (hereinafter referred to the MIM type), the surface conducting type electron-emission device, and the like.
As an example of the FE type, an electron-emission device disclosed in W. P. Dyke & W. W. Dolan, “Field Emission”, Advance in Electron Physics, 8, 89 (1956), C. A. spindt, “PHYSICAL Properties of thin-film field emission cathodes with molybdenum cones”, J. Appl. Phys., 47, 5248 (1976), or the like is known.
As an example of the MIM type, an electron-emission device disclosed in C. A. Mead, “Operation of Tunnel-Emission Devices”, J. Appl. Phys., 32, 646 (1961) or the like is known.
As an example of the surface conducting type electron-emission device type, an electron-emission device disclosed in M. I. Elinson, Radio Eng. Electron Phys., 10, 1290 (1965) or the like is known.
A surface conducting type electron-emission device is to utilize a phenomenon that generates electron emission by flowing electric current to a thin film with a small area formed on a substrate in parallel with the surface of the film. As the surface conducting type electron-emission device, one using an SnO2 thin film by Elinson, et al. mentioned above, one using an Au thin film [G. Dittmer: “Thin Solid Films,” 9, 317 (1972)], one using an In2O3/SnO2 thin film [M. Hartwell and C. G. Fonstad: “IEEE Trans. ED Conf.”, 519 (1975)], one using a carbon thin film [Araki Hisashi, et al.: Shinku, Vol. 26, No. 1, page 22 (1983)] and the like are known.
For the manufacture of an image displaying apparatus using the above-mentioned electron-emitting device, a process for manufacturing a display panel is used which comprises the steps of: preparing an electron source substrate on which such electron-emitting devices are arranged in matrix as an RP and preparing a phosphor substrate to be an FP provided with phosphors that emit light due to excitation by an electron beam; disposing the FP and the RP in opposing positions by disposing a spacer providing an envelope and an anti-atmospheric pressure structure such that the electron-emitting elements and the phosphors will be inside and; sealing the inside using a low-melting point material such as frit glass, indium or the like as a sealing material; and sealing off a vacuum exhaust pipe provided in advance after vacuum exhausting the inside from the vacuum exhaust pipe.
The manufacturing method according to the conventional art described above requires considerably long time for manufacturing one display panel, thus is not suitable for manufacturing a display panel inside of which requires the vacuum degree of 1×10−6 Pa or more.
The drawback of this conventional art was solved by a method described, for example, in the Japanese Patent Application Laid-open No. 11-135018.
In the method described in the Japanese Patent Application Laid-open No. 11-135018, since only a step of sealing two substrates after positioning an FP and an RP in a single vacuum chamber is used, the above-mentioned other steps such as bake processing, getter processing, electron beam clean processing and the like that are necessary for preparing a display panel needs to be applied in the single vacuum chamber respectively. In addition, since movements of the FP and the RP between vacuum chambers are performed upon loosing evacuated state into non-vacuum state, each vacuum chamber is evacuated every time when an FP and an RP are carried therein. Due to these reasons, manufacturing process time is long. Therefore, considerable reduction of manufacturing process time has been required, and at the same time, it has been required to attain high vacuum degree of 1×10−6 Pa or more in a display panel during a final manufacturing step in a short time.